Large-sized off-road dump trucks typically used in a mine and the like are equipped with a body that is supported by a chassis frame in a liftable manner. Earth, sand and the like are loaded in the body and are unloaded by raising the body after being transported to a predetermined site.
In order to keep the earth and sand from adhering on an inner surface of the body when the earth and sand are unloaded, exhaust gas from an engine is circulated in an exhaust gas flow path defined by an inner space of ribs provided in the body, thereby heating the body. Heating the body vaporizes water contained in the earth and sand so that the earth and sand is dried. Thus, releasability of the earth and sand from the inner surface of the body can be enhanced (see, for instance, Patent Literature 1).
The earth and sand carried in the body is likely to be adhered on a corner defined at a border between a front plate and a bottom plate of the body or on corners defined by the front plate, the bottom plate and right or left side plates. Accordingly, the inner space of the ribs provided corresponding to the corners is used as the exhaust gas flow path.